TenneT Starts Laying Subsea Cable for Nordergründe OWF

Grid Connection

TenneT has started installing a 28-kilometre subsea cable which will connect the 111MW Nordergründe offshore wind farm with the onshore substation near Inhausen, Germany.

Source: TenneT

The 155kV export cable was pulled into an empty tube below the dike near Hooksiel on 3 May, after which the cable laying works started and are still on-going. The cable is being laid with a 16 metres high, 80 tonne jetting sled.

As the offshore substation of the wind farm Nordergründe has not been erected yet, the last part of the sea cable will be stored on the sea bed in the wind farm area approximately 15 kilometres east of the island of Wangerooge.

Once the offshore substation is completed, the cable will be connected to it and the grid connection will be taken into operation. TenneT plans to take the grid connection into operation within 2016, which corresponds to the project’s schedule.

Prior to the laying of the cable, the route was cleared of unexploded ordnance from WWII.

Nordergründe is TenneT’s third offshore grid connection in the twelve sea mile zone in Lower Saxony. As it is only 30 kilometres away from the coast, the most efficient connection method is via AC cables.

A 4-kilometre land cable which will connect to the onshore substation near Inhausen was laid in 2012, and the substation was constructed in 2013.

Nordergründe, being developed by wpd, comprises a total of 18 Senvion Type 6.2M126 wind turbines. The first turbine foundation was installed at the site earlier this month.

The wind farm is scheduled for commissioning in 2016.